Feed chuck



Nov. 21, 1950 A. J. DADDONA 2,530,568

FEED cnucx Filed July 17, 1946 I N VEN TOR.

Patented Nov. 21, 1950 UNITED STATES PATENT OFFICE FEED CHUCK Anthon'y J. Daddona, Elmira, N. Y., assignorto 'Hardinge Brothers, Inc., Elmira, N. Y. Application July 17, 1946, Serial No. 684,390

3 Claims.

1 This invention relates to improvements in feed chucks of the kind commonly used for advancing work in automatic screw machines or the like, and more particularly to feed chucks of the type in which removable work engaging pads are used at the ends of the spring fingers of the chuck.

With some types of feed chucks, it is difiicult to pry the spring fingers apart for the purpose of removing or replacing the Work engagingpads. This is particularly the case in large feed chucks in which the spring fingers are designed to exert heavy pressures against the work. There is also theda'nger with feed chucks that the implement used for 'separating-theends of the spring fingers may slip out of place, whereupon the spring fingers will close and injure thehands of a person working on the chuck. 7

One of the objects of this invention is to provide means of improved construction for facilitating the spreading apart of the spring fingers for the purpose of inserting and removing the work engaging pads therein. Another object of the invention is to'provide means for spreading the fingers of feed chucks which will positively hold the'fin'gers ih'se'parated positions, to avoid accidents resulting from the unintentional closmg of the spring fingers. A further object of this invention is to provide feed chucks of this type with work engaging pads of improved construction which permit the use of finger sepa rating implements near the ends of the spring fingers. provide an implement of improved construction for use in connection with the separation or spreading of the spring fingers of a feed chuck. Other objects and advantages will appear from the following description and claims.

Inthe accompanying drawings, which illustrate byway of example oneembodimeht of this invention:

Fig. 1 is 'a side 'view of a-feed'chuck embodying this invention and-showing'the same engaging a workpiece.

Fig.2 is an end view thereof, taken on line 2 -2 Fig. 1. V

Fig. 3 is a perspective view of a tool or implement for spreading or separating the spring fingers.

Fig. 4 is a fragmentarylongitudinal sectional elevation of the feed chuck embodying this invention, the section being taken on line 4-4, piglz v Fig. 5 is a fragmentary side elevation of a feed chuck showing the fingers thereof separated by means of the implement shown 'in Fig. 3.

A further object of this inventio'nis to Fig. 6 is a transverse section thereof, on lin'e 6-5, Fig. 5.

The improvements embodying this invention may-be applied to any suitable or desired type of feed chuck, that shown for purposes of illustration including the usual tubular body portion 8 having one end thereof threaded as shown at 9 for attaching the feed chuck to a part of an automatic screw machine or other type of machine which moves the feed finger back and forth for feeding the Work It]. The feed chuck maybe provided with any desired number of feed fingers l I, these fingers being formed by means of longitudinal slots [2 cut into the feed chuck from one end thereof and terminating at a distance new] i the other end. The feed chuck is preferably pro vided at the outer or free ends of the feed fingers H with suitable work engaging pads l5, one pad being provided for each spring finger, and the width of each pad being preferably coextensive with the width of the finger on which it is used. These pads [5 have their inner faces formed to engage the work ID and the pads are formed so as to engage the spring fingers to hold the pads in place with relation to the fingers. Any suitable or desired means may be employed for holding these pads on the spring fingers, and in the construction shown, each finger is provided with an aperture it near the end thereof and each pad is provided on the outer face thereof with a projection I! formed to extend into the aperture I6. It will be noted that when the work is positioned in the feed chuck, the spring fingers will press the pads against the work with sufficient force to ensure the feeding of the work when the feed chuck is reciprocated, and this pressure of the pads against the work also serves to hold the projections I i in the holes or apertures IS in the spring fingers. When the work is removed from the feed chuck, the resiliency of the spring" to move toward each other and will then press the adjacent edge portions !9 of the pads against each other. Pads and holding means of any other fingers causes the free ends of the spring fingers suitable or desired construction may be employed if desired. I?

In order to facilitate the removal of the pads from the spring fingers by separating the free ends of the fingers from each other, various tools or implements have heretofore been provided which extend into the slots I2 of the feed chuck and by means of which the outer ends of the.

spring fingers may be pried apart. Generally such tools or implements are applied to portions of feed chucks intermediate of the ends thereof,

for the reason that the pads themselves interfere with the insertion of tools or implements into the outer ends of the slots to enable the spring fingers to be pried apart. In accordance with this invention, however, the implement for spreading or separating the outer ends of the spring fingers is constructed to operate very near to the outer ends of the spring fingers, where the minimum amount of force is required to separate the fingers, this being particularly desirable when this invention is used in connection with large feed chucks in which a great deal of force is required to separate the outer ends of the spring fingers.

In accordance with this invention, enlargements are provided in the slots l2 adjacent to the outer ends thereof, formed by cutting recesses in the spring fingers adjacent to the ends thereof, two such recesses being shown at opposite edge portions of adjacent spring fingers and facing each other, but if desired, the enlargement may be formed by a single recess in only one of two adjacent edges of the spring fingers. These enlargements have parallel edges extending parallel to the edges of the slots l2 and are of suficient length to enable an implement to be inserted into the enlargement, and the enlargement is preferably so located with reference to the slot 42 that the enlargement does not extend to the open end of the slot l2, so that a portion of the narrow slot 12 extends beyond the enlargement to the outer end of the feed chuck. An implement with a flat end portion may, consequently, be inserted into the enlargement 20 and turned through approximately 90 degrees so as to pry the spring fingers apart and the fact that the enlargement does not extend to the end of the feed chuck would prevent the implement from slipping out of the slot lengthwise thereof. I

It is, however, also desirable to provide means for preventing the instrument from slipping out of the enlargement 20 laterally or radially of the feed chuck, and for this purpose, an implement may be provided as illustrated particularly in Figs. 3, 5 and 6. This implement may have a handle 24 of any suitable form and may have an end portion thereof bent over and provided at its outer end with a key 25 which includes two fiat sides, the key being of such size that it can readily be inserted into the enlargement 20 with the fiat sides extending substantially parallel to the length of the feed chuck. It will be noted that the key portion of the implement is preferably of approximately T-shape being provided with notches 29 in the sides thereof, thus forming lateral extensions 28 at the end of the key portion. The implement 24 is preferably made of stock that is substantially circular in cross section and the key may be formed by first cutting an annular groove adjacent to the end portion of the implement and then milling or otherwise cutting the metal from opposite sides of the key portion, thus forming a fiat neck terminating at its outer end in an enlarged head. When the key portion of this implement is inserted into the enlargement 20, the portion of circular cross section of the end of the implement acts as a stop to limit the extent to which the key may be inserted into the enlargement. When the implement is turned through approximately a right angle into the position shown in Figs. 5 and 6. the projections 28 forming the head of the T- shaped key will be in positions to engage the inner surfaces of adjacent spring fingers l I so that removal of the key portion laterally of the feed chuck is absolutely prevented. This, therefore, makes it safe to operate even on a large size feed chuck by means of the implements shown, since it is impossible for the implement to move out of its finger spreading position and thus inadvertently to permit the fingers to come together.

Since the pads ordinarily fit snugly within the inner surfaces of the spring fingers, it is necessary to provide some means for permitting the key portion of the implement to be completely inserted into the enlargement 20 of the slot, so that the head of the key will be Within the interior of the feed chuck, and for this purpose, the outer surfaces of the pads near their longitudinal edge portions are provided with recesses 35 which extend from the inner ends of the pads adjacent to the outer ends thereof. These recesses must be of ample depth to permit the head of the T-shaped key to enter into the same and also considerably wider than the heads of the keys to permit the pads to move relatively to the key portions of the implements as shown in Fig. 6, so that the pads can be moved lengthwise out of the feed chuck, after their projections I! have moved out of the hole It in the spring fingers, and so that pads may be placed into the feed chuck. Consequently, because of these recesses 39 in the pad, the implements can readily be inserted into the enlargements 2% of the slots and turned to pry the ends of the spring fingers apart, and the recesses also make it possible to insert pads into and remove pads from the feed chuck.

In the use of the construction described, a number of implements is used corresponding to the number of slots and spring fingers in the feed chuck. These implements may be swung one at a time into positions to pry the spring fingers apart. This requires materially less force than would be required if a single implement were used to extend through two slots and pry both sides of the spring fingers apart at the same time. Furthermore, the construction described is such that the implement may be inserted into an enlargement located near the outer or free ends of the spring fingers which again reduces the amount of force required to spread the spring fingers apart. By providing key portions on the implements which are so constructed that the implements cannot slide or accidently move out of their finger spreading positions, the danger of accidents is very materially reduced.

I claim:

1. An improved feed chuck with a passage therethrough and comprising a plurality of spring fingers all anchored at one end and free at their other ends, the free ends being separated by slots running lengthwise from said free ends, and a work engaging pad removably fitting the inner face of each free end of a finger and extending lengthwise along it for a substantial distance, each slot having an enlargement in width in the portion past which the pads extend and spaced from the free open end of the slot by an unenlarged portion, each of said pads being provided on its outer curved surface adjacent to its edge portions with recesses extending lengthwise from the inner ends of said pads to and along said enlargements of said slots, to form spaces between said spring fingers and said pads, whereby when a key with a flat end and lateral extensions is inserted in said enlargement and turned to spread said fingers, said lateral extensions on the inserted free end of the key may turn in said space to lie along the inner face of a finger and prevent endwise removal of the key from the slot while the fingers are spread by the key.

2. The combination of a feed chuck having a plurality of spring fingers anchored at one end and free at their outer ends, said spring fingers being separated from each other by slots extending lengthwise from said free ends, work engaging pads removably fitting the inner faces of the free end portions of said fingers, each slot having an enlargement in width in a portion past which the pads extend and spaced from the free open end of the slot by an unenlarged portion, each of said pads being provided on its outer curved surface adjacent to its edge portions with recesses extending lengthwise from the inner ends of said pads to and along said enlargements of said slots to form spaces between said spring fingers and said pads, whereby an implement for spreading apart said free ends of said spring fingers and including a shoulder and a T-shaped fiat key formed on the end thereof and extending beyond said shoulder, may be inserted in a direction radial to said feed chuck into said enlargement of said slot with the fiat faces thereof extending substantially parallel with said slot, said implement when turned through approximately 90 degrees causing said key portion to spread said fingers apart and causing the head of the T-shaped portion to enter into said spaces formed by said recesses in said pads, said head of said key portion being retained in said spaces against movement both lengthwise of said slot and radially of said feed chuck.

3. An improved feed chuck with a passage therethrough and comprising a plurality of spring fingers all anchored at one end and free at their other ends, the free ends being separated by slots running lengthwise from said free ends, and a Work engaging pad removably fitting the inner face of each free end of a finger and extending lengthwise along it for a substantial distance, each slot having an enlargement in width in the portion past which the pads extend, portions of said spring fingers and said pads being spaced apart adjacent to said enlargements, whereby a key with a fiat end and lateral extensions at its outer end may enter into said enlargement and be turned through approximately degrees to spread said spring fingers apart, and whereby said enlargements of said key when the same is turned, will enter into the spaces between said pads and said spring fingers and underlie the edges of said enlargements to prevent removal of said key from the slot when said spring fingers are spread apart.

ANTHONY J. DADDONA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

